The present invention is directed to slide valves utilized for controlling high temperature and high velocity flow.
Slide valves utilized in controlling high temperature and high velocity flow of products through the valve have a number of disadvantagesxe2x80x94for example, require seat plates and seat plate bolting, have seat plate distortion, and the utilization of bolting that is under load due to differential pressure in the valves and are only as strong as the bolting system strength of bolts resulting in seat plate distortion, do not have a positive seal against by-pass from differential pressure, do not allow for proper alignment of the orifice plate, and do not provide for future expansion of the port opening.
The following patents represent the current state of the art with respect to slide valves.
Treichel et al., U.S. Pat. No. 5,301,712, discloses background information concerning slide valves, their applications, problems and the like of slide valves in the field of use of the present invention to which reference is made. It also discloses a slide valve assembly including an orifice and a slide valve slidable in the guides of the orifice plate assembly. The orifice plate assembly is slidable into and out of position in the slide valve housing through a side opening via grooves formed in the inner walls of the housing.
Houston et al., U.S. Pat. No. 5,123,440, discloses a slide valve for use in high temperature environments. The mounting ring of the slide valve is propped against the bed plate by a plurality of columns which are adjustable by screws connecting gussets to rails upon which the slide or disc slides.
Wiese, U.S. Pat. No. 5,096,099, discloses a slide valve with an adjustable cover that is connected at an opening to a container by a plurality of socket head screws.
Owens et al., U.S. Pat. No. 5,082,247, discloses a split seat gate valve located within a length of pipeline. The valve is disposed between flanged openings in the pipeline and is secured by a plurality of bolts.
Jandrasi, U.S. Pat. No. 4,693,452, discloses several embodiments of slide valves for high corrosive environments. In the most relevant embodiments, the orifice plate and guide rails of the slide valve are attached to the valve housing by a plurality of bolts that run parallel to the flow direction to connect the valve assembly.
Purvis, U.S. Pat. No. 4612,955, discloses an edge ear tab used to prevent corrosion around the orifice in high temperature applications. Slides are slidably mounted in rails which are bolted to the valve housing.
Graf et al., U.S. Pat. No. 4,542,453, discloses a slide valve for high temperature gas lines. The internals are removed only by disassembly of the valve housing.
Jandrasi et al., U.S. Pat. No. 4,531,539, discloses a slide valve. The orifice plate of the slide valve is releasably secured in place by bolts running parallel to flow direction.
Jandrasi et al., U.S. Pat. No. 4,512,363, discloses a valve assembly wherein the valve internals (orifice assembly, valve seat, guides, and slide) are removably secured to the valve body by a clamping action. The clamping action is established by a valve liner which engages the orifice assembly and presses it into abutment with the valve body. A lower flange of the liner is removably positioned between the slide valve body and outlet member.
Jandrasi et al., U.S. Pat. No. 4,458,879, discloses a valve wherein the valve internals are held in position by a clamping action of a quick make-up cylinder. The orifice plate with guides for the slide is clamped to the valve body by a quick connect cylinder that screws into the valve body.
Worley et al., U.S. Pat. No. 4,253,487, discloses a slide valve using a pair of opposing discs to control fluid flow through the valve. The guide rails within which the discs slide are held in place by bolts that run parallel to the flow direction.
It would be advantageous to provide a slide valve which eliminates bolting that is under load to differential pressures in the valve, which is much stronger than a bolted system for maintaining the internals in position, which has positive sealing against by-pass from differential pressure, in which no seat plate is utilized thereby eliminating distortion from a seat plate, allows for future expansion of the port, is easier to remove and replace internals rather than one utilizing bolts which often gall, break, or are difficult to remove and replace, in which the internals are maintained properly aligned, and which may be used for all size valves.
The present invention is directed to such a slide valve in which product flow is controlled through the valve. The internals of the slide valve comprise the orifice plate with a circumferentially-extending stub welded to it, and the guide assembly for the slide or disc, the orifice plate circumferential stub being connected by a weld assembly to an internal support cone which in turn is welded to the valve body. Preferably the orifice plate and the guide assembly are welded together into a monolithic or unitary structure, or the guide assembly is supported by the orifice plate by wrap around guides bolted or pinned to the orifice plate without the bolts or pins bearing any load. The internals, guide assembly, and orifice plate may be removed quickly and easily by cutting a welded connection of the weld assembly to the stubs and replaced by rewelding the stub connection to the support cone. The circumferentially extending stub can be welded either to the inside or outside of the internal end of the support cone. This permits high temperatures (1,000xc2x0 F.+) and high pressure (50 psi+) transfer of product through the valve assembly having the above advantages and features. Further details and aspects of the slide valve of the present invention are set forth in the following description of preferred embodiments.
Accordingly, it is an object of the present invention to provide such a slide valve which eliminates bolting under load subject to differential pressure in the valve.
It is a further object of the present invention to provide such a slide valve which is much stronger than slide valves using a bolted system to maintain the internals in place in the valve.
It is yet a further object of the present invention to provide such a slide valve which provides a positive seal against by-pass from differential pressure.
A further object of the invention is to provide such a slide valve which eliminates a seat plate and seat plate bolting and hence has no seat plate distortion.
A still further object of the invention is the use of stubs welded to the orifice plate and support cone which allows proper alignment of the port or orifice in the orifice plate.
A still further object of the present invention is the provision of such a slide valve in which the orifice plate and the valve slide are a unitary or monolithic structure.
It is still a further object of the present invention to provide such a slide valve in which the internals are easier to remove and replace than in current slide valves.
A further object of the present invention is that the internal parts are maintained in proper alignment.
It is yet a further object of the present invention to provide such a slide valve which may be utilized for all sizes of valves, which is suited for large, small, and medium sized valves.
Other and further objects, features, and advantages are set forth and are inherent in the slide valve as set forth throughout the specification and claims.